﻿.lst0708 #flexbox {
     display: -ms-flexbox;
     -ms-flex-wrap: wrap;
     width: 800px;
     height: 300px;
     border: 3px solid lightgray;
     -ms-flex-pack: start;
}

.lst0708 #flexbox > div {
    border: 1px solid black;
    width: 100px;
    height: 100px;
    margin: 5px;
}
